Device to prevent the formation of ice on aerodrome runways



2 Sheets-Sheet l Filed March 5, 1952 w NN Pl'll 24, 1956 o. F. BCKSTRM 2,743,057

DEVICE TO PREVENT THE FORMATION OF ICE ON AERODROME RUNWAYS Filed march 5, 1952 2 sheets-sheet 2 #lng /NVE/VTOR ggwwww greater thickness than that of the runways.

United States vPatent O DEVICE T PREVENT THE FORMA'HN 0F ICE ON AERODROME RUNWAYS Ove Fridolf Bckstrm, Goteborg, Sweden Application March S, 1952, Serial No. 275,004

2 Claims. (Cl. 237-69) The present invention relates to a device serving to prevent the formation of ice on landing fields for aircrafts and to de-ice and warm such elds respectively.

The main feature of the invention is the provision of coiled pipes, connected in parallel and communicating with a steam boiler, next underneath the landing eld, each pipe coil being connected to a conduit from the steam boiler by means of a valve, which is adapted to close at pipe breaks in the coiled piping, and to a return conduit to the steam boiler by means of a return valve. The coiled pipes are preferably carried by elastic or yielding supports provided upon a bed of considerably Preferably, a course of heat insulating material is provided underneath the coiled pipes. Possible heating elements Iin buildings etc. may be connected to the return conduit to the steam boiler.

An embodiment of the invention will be described l in the following text, reference being had therein to the connection by means of valves to the pipe conduits'.

leading from and to a steam boiler plant, the latter indicated diagrammatically in claim-dotted lines, and

Fig. 2 shows on a larger scale part of an aviation runway provided with the device.

Next underneath the top layer of the runway there are provided coiled pipes 2, connected in parallel and communicating with a steam boiler 3. One end of each pipe coil is connectedl to a pipe conduit 4 from one steam boiler by means of a valve 5, which is adapted to close if pipe breaks occur in the pipe coil. By means of a check valve 7, the other end of each coil is connected to a return pipe 6 leading to the steam boiler. The valves 5 and 7 will shut off the pipe coil automatically if thte latter is injured by bombing. v

The pipe coils 2 are carried by elastic supports 8 placed upon the bed 9, which is considerably thicker than the runway 1. This allows a certain springing of the runway 1 at a bomb hit and thus damps the shock. l

On top of the bed 9 and beneath the pipe coils 2 is a layer 10 of heat insulating material, which prevents the downwards conduction of heat.

The heat emitting medium consists of overheated steam or water. When steam is used, the system should be balanced in such a manner that condensation cannot take place in the coils, as the steam should be overheated throughout the piping in order to prevent water deposition. When the steam has passed the pipe coils 2 underneath the runway 1, it is conducted through the heating elements 11 in buildings or the like. The condensate is collected in a tank 12 and is pumped into the steam boiler 3 by means of a feed pump 13.

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InA the valve 5 (Fig. 2), which is arranged to close at breaks in thepipe coil 2, the spindle 1S carrying the shut-off cone 14 is equipped with a piston 16, which is movable in a chamber 17. Above the piston, the chamber is provided with a pipe line 18 connected to the feed pipe of the coil before the valve 5, and below the piston the chamber is provided with a pipe line 19 connected to the feed pipe of the coil after the valve 5. If a break occurs in the pipe coil 2, the pressure in the pipe line 19 will become lower than the pressure in the pipe line 18 and, consequently, thepiston 16 will be pressed downwards in Fig. 2 andl bring the shut-off cone 14 against its seat.

The valve 5 may also be operated by hand, in which case the cone spindle 15 and the wheel spindle 20 must be interconnected by means of a hook.

' In the feed pipe of each pipe coil is a manually operated valve 21 before the valve 5, and in the discharge pipe of each pipe coil is aA manually operated valve 22 after the check valve 7.

In the pipe line 19 extending from the feed pipe of the pipe coil after the valve 5 to the chamber 17 is a threeway cock 23. During operation of the system, said cock should be adjusted as indicated in Fig. 2. By manyual adjustment of the three-way cock 23, the part of the chamber 17 located beneath the piston 16 can be connected to the surrounding atmosphere, whereby the valve 5 is closed very rapidly.

I t is to be understood that the invention is not conned to the embodiment described in the specification and illustrated by the drawing, but that said embodiment may be varied in many ways without departure from the scope and spirit of the invention.

A device according to the invention makes it possible to keep aviation places free from ice even in polar regions in winter time.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

l. Ina heated runway of an airport, the combination of aiirrn bed, elastic supports projecting upwardly from said bed, a pipe coil system supported on said supports above and spaced from said bed to allow limited yielding under violent shock, a relatively ilexible surface layer resting on said resiliently supported pipe coil system, a steam boiler communicating with said pipe coil system for delivering superheated steam thereinto, said pipe coil system comprising a plurality of parallelly coupled pipe coils each having its respective ends connected to inlet and outlet headers, a valve in the inlet of each of said pipe coils, said valve having means responsive to the fall of pressure in the respective coil to close upon breaks in the corresponding coil, and a check valve at the outlet end of eachof said pipe coils preventing return flow through the corresponding coil. 2. In a heated runway as claimed in claim 1, a layer of heat-insulating material beneath said pipe coil system.

References Cited in the le of this patent UNITED STATES PATENTS 899,078 salmon sept. 22, 1908 1,424,949 Stork Aug. 8, 1922 1,456,946 Stork May 29, 1923 2,505,622 McKee Apr. 25, 1950y 2,570,226 Geringer Oct. 9, 1951 

